Which Jumper Cable Color Goes First?

by | Last updated on January 24, 2024

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Attach the

red jumper first

. Start by clamping one red cable to the positive side of the that won't start. Then attach the other red clamp to the positive side of the working battery. Next, clamp one black cable to the negative side of the working battery.

Do you hook up the positive or negative first?

When disconnecting the cables from the old battery,

disconnect the negative first, then the positive

. Connect the new battery in the reverse order, positive then negative.” When you are replacing your car battery, It isn't always easy to remember the order in which to disconnect and reconnect the .

Do you connect red or black first?

When removing the old battery, remember to first disconnect the cables from the negative terminal, which is

usually black

and has a minus (-) sign then disconnect the cables from the positive terminal, which is usually red and has a plus (+) sign.

What happens if you connect negative first?

Negative pole first:

Whole car (except a few parts like the positive pole) are connected

. Any mistake with the other lead will lead to a short. … If you mess up by touching the car with the other lead nothing will happen.

Which battery terminal do I connect first?



Positive first, then negative

. When disconnecting the cables from the old battery, disconnect the negative first, then the positive. Connect the new battery in the reverse order, positive then negative.”

What happens if you disconnect the positive terminal first?

It's important to

disconnect the negative side of the battery first

, otherwise you can cause an electrical short if the positive is removed first.

What happens if I connect positive to negative?

Connecting the positive terminal of each battery to the negative terminal of the other battery will result in

a huge surge of electrical current between the two batteries

. … The heat can melt internal and external battery parts, while the pressure from the hydrogen gas can crack the battery casing.

Does the order of jumper cables matter?


It is important to connect the cables in that order

, and it is safest to connect the negative (black) clamp as far from the battery as possible, in order to reduce the risk of sparking that could cause a fire or explosion.

What happens if you hook a battery up backwards?

When a car battery is connected backward,

a fuse designed to protect vehicle electronics should blow

. If your vehicle doesn't have a fuse (almost all cars do) designed for this purpose, you will send electrical current backward through systems in your car, including ECU, transmission control unit, and more.

Why don't you connect the negative when jumping a car?

Why can't you connect the black jumper cable to the dead battery's negative (–) terminal? … This is so you

can avoid sparks from occurring near the battery where flammable hydrogen gas may be present

, resulting in a possible explosion.

Do I connect the ground wire first?

Even plastic electrical boxes may have a metal strip for ground that connects to the metal screw receptors.

Check that first

. If not, connect the ground from the panel to the fixture ground with a marette (just like the power wires) and twist the fixture ground around the green screw.

Which cable do you take off first when jumping a car?

Disconnect the cables in the reverse order: First

remove the negative cable

from the car you jumped, then the negative cable from the car with the good battery. Then remove the positive cable from the car with the good battery (don't touch a grounded part of either car with the clamp of the positive cable).

Is it OK to just disconnect the positive terminal?

You will be fine.

Disconnecting either cable works

. The reason they say to disconnect the negative and not the positive is because while taking the positive connection off with a wrench if you happen to touch anything with the wrench while it's on the positive terminal it can arc and be dangerous.

What happens if you don't disconnect the negative battery cable?

Contact between the negative battery terminal and the battery, even if the cable is not clamped onto the battery,

may reactivate the electrical system within the car

. This would negate all the reasons you have done this much work to ensure the cable is disconnected.

Why do you connect the positive terminal first?

Connect positive first, negative having

less potential won't arc

. The higher the voltage, the greater the chance of arcing and fusion. On a car if negative first and you are touching any metal part of car, when attaching positive there is possibility of arcing through you. Your body becomes part of the circuit.

Can reverse polarity damage electronics?

This can damage the battery and other electrical components. Any battery-powered product you use while it's plugged in will be energized through its full circuit and thus a potential source of electrical shock. Reverse polarity

can cause PCB damage and even PCB failure

, yet the damage can be hard to see.

David Evans
Author
David Evans
David is a seasoned automotive enthusiast. He is a graduate of Mechanical Engineering and has a passion for all things related to cars and vehicles. With his extensive knowledge of cars and other vehicles, David is an authority in the industry.